Iowa State Tree

Oak (Recognized Bur Oak)

(Fagaceae Quercus macrocarpa) Recognized

Adopted in 1961.

The oak tree was chosen by the 59th Iowa General Assembly as Iowa's official
tree on March 13, 1961.

Although Iowa did not designate a specific species of oak as its state tree, many people
recognize bur oak, (Fagaceae Quercus macrocarpa,) as the state tree
since it is the most widespread species in the state. According to Chris Feeley at The Department
of Natural Resources Ecology and Management, the bur oak is the only native oak that is found
in all Iowa counties. In the late 1800s, the bur oak was selected as the most typical tree
of Iowa for planting in San Francisco's Golden Gate Park.

Iowa General Assembly notes,

"The Iowa General Assembly chose the oak because it is abundant
in the state and serves as shelter, food and nesting cover for many animals and birds. It
is difficult to find a tract of natural woodland in Iowa that does not have in it at least
one species of oak. No other group of trees is more important to people and wildlife. Acorns,
the nuts of oak trees, are a dietary staple of many animals and birds. Deer, wild turkeys,
pheasants, quail, wood ducks, raccoons, squirrels, chipmunks, bluejays, nuthatches, grackles
and several kinds of woodpeckers are a few of the species that depend on acorns for a significant
portion of their diet."

Iowa State Tree: Bur Oak

Quercus
macrocarpa, the Bur oak, sometimes spelled Burr oak, is a species of
oak in the white oak section Quercus sect. Quercus, native to North America in
the eastern and midwestern United States and south-central Canada. This plant is also called
Mossycup oak and Mossycup white oak.

It occurs from the Appalachian Mountains west to the middle of the Great Plains, extending
to central Texas, across southernmost Manitoba, Ontario and Quebec, east to the Atlantic Coast
in southern New Brunswick and down the coast to Delaware.

The mighty, majestic oak has, throughout the centuries, been the subject of story, song
and proverb. More than 80 species of this beautiful tree are found in North America. All oaks
are deciduous trees with toothed leaves and heavy, furrowed bark. The fruit is, of course,
the acorn. Like other deciduous trees, most oaks shed their leaves in fall. However, in warmer
areas of the continent, some varieties, the ‘live' oaks, keep their greenery throughout
the winter. Oaks have always been economically important for their hard, strong wood which
has a multitude of purposes including furniture and flooring. Oaks also have landscape uses
although mature trees can dominate smaller sites.

Identification of the Bur Oak

Leaf: Alternate, simple, 6 to 12 inches long, roughly obovate in shape, with
many lobes. The two middle sinuses nearly reach the midrib. The lobes near the tip resemble
a crown. Pale pubescence is present below.

Flower: Male flowers are green, borne in naked catkins, 2 to 4 inches long. Female
flowers are reddish and appear as single spikes. Appearing shortly after the leaves.

Fruit: Acorns are quite large (1 1/2 inches long) and 1/2 enclosed in a warty
cap that has a long-fringed margin. Maturing in one year, dropping August to November.